Recently one of our customers experienced his throttle control binding up while taxiing. The aircraft was brought back to the hangar and uncowled to investigate the situation. During that time, the controls began to work again. This was very puzzling, and took some thought as to what might cause it to work fine during all times, accept during taxiing.
It was determined that the extra heat generated in the cowling, during taxiing on a hot summer day, was causing the small 10-32 rod end bearing attaching the control linkage to the fuel servo throttle arm to bind. This was verified by using a heat gun to warm up the rod end and note it’s increase in friction.
A review of the type of rod ends currently supplied, is being done. If any one else has experienced such binding of the engine controls, please let us know, so that we can determine how wide spread the problem might be.